492 research outputs found
Towards Autonomous Inspection of Space Systems Using Mobile Robotic Sensor Platforms
The space transportation systems required to support NASA's Exploration Initiative will demand a high degree of reliability to ensure mission success. This reliability can be realized through autonomous fault/damage detection and repair capabilities. It is crucial that such capabilities are incorporated into these systems since it will be impractical to rely upon Extra-Vehicular Activity (EVA), visual inspection or tele-operation due to the costly, labor-intensive and time-consuming nature of these methods. One approach to achieving this capability is through the use of an autonomous inspection system comprised of miniature mobile sensor platforms that will cooperatively perform high confidence inspection of space vehicles and habitats. This paper will discuss the efforts to develop a small scale demonstration test-bed to investigate the feasibility of using autonomous mobile sensor platforms to perform inspection operations. Progress will be discussed in technology areas including: the hardware implementation and demonstration of robotic sensor platforms, the implementation of a hardware test-bed facility, and the investigation of collaborative control algorithms
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Carbon Catcher Design Report
Overview. The design of the overall Carbon Catcher project can be separated into four distinct systems, each of which is assigned a specialized committee. The committee names and responsibilities are listed below:
Air Mover
The overall goal for the Air Mover committee is the design of the turbine assembly. As the overall goal of the project is to collect and separate carbon dioxide from the air, one of the most important parts is to actually get the air to pass through the carbon-catching
membrane. Passive air would not give a significant enough yield rate to make the carbon dioxide collection rate impactful, thus air must be sucked through a vacuum/turbine.
Membrane
The goal of Membrain is to create a membrane that can filter out CO2 through various methods. These methods are limited, due to there being such variety, to certain techniques and membrane material types that have been decided, prior, by the committee. Most membranes will be geared towards utilizing temperature and pressure along with gaseous speed and flow rate. In addition, examining certain treatments, such as regeneration of material, and replacements will be looked into as well, to see how it fares in sustainability.
Carbon Storer
The Carbon Storer committee will design a store and transport system for fluid CO2 after it is extracted from the atmosphere. Primary considerations include geological solutions, cost-effective materials, and analysis methods to improve overall capacity and efficiency. Additionally, the committee will select an environmentally and economically sustainable method of recycling the captured CO2.
PyControl
The PyControl committee will design a series of sensors and actuators, which will primarily support the sequestration and pipeline systems present in the Carbon Storer Committee and direct air capture system in Air Mover. The design can be broken into four control layers: Input/Output, Field Controllers, Data, and Supervisory.
Goal
The overarching goal of Carbon Catcher is to design a cost-effective, scalable atmospheric carbon dioxide removal system that is capable of being deployed in a variety of urban environments and may fit a variety of different customer requirements or requests
Bluetooth Mesh under the Microscope: How much ICN is Inside?
Bluetooth (BT) mesh is a new mode of BT operation for low-energy devices that
offers group-based publish-subscribe as a network service with additional
caching capabilities. These features resemble concepts of information-centric
networking (ICN), and the analogy to ICN has been repeatedly drawn in the BT
community. In this paper, we compare BT mesh with ICN both conceptually and in
real-world experiments. We contrast both architectures and their design
decisions in detail. Experiments are performed on an IoT testbed using NDN/CCNx
and BT mesh on constrained RIOT nodes. Our findings indicate significant
differences both in concepts and in real-world performance. Supported by new
insights, we identify synergies and sketch a design of a BT-ICN that benefits
from both worlds
The Family of MapReduce and Large Scale Data Processing Systems
In the last two decades, the continuous increase of computational power has
produced an overwhelming flow of data which has called for a paradigm shift in
the computing architecture and large scale data processing mechanisms.
MapReduce is a simple and powerful programming model that enables easy
development of scalable parallel applications to process vast amounts of data
on large clusters of commodity machines. It isolates the application from the
details of running a distributed program such as issues on data distribution,
scheduling and fault tolerance. However, the original implementation of the
MapReduce framework had some limitations that have been tackled by many
research efforts in several followup works after its introduction. This article
provides a comprehensive survey for a family of approaches and mechanisms of
large scale data processing mechanisms that have been implemented based on the
original idea of the MapReduce framework and are currently gaining a lot of
momentum in both research and industrial communities. We also cover a set of
introduced systems that have been implemented to provide declarative
programming interfaces on top of the MapReduce framework. In addition, we
review several large scale data processing systems that resemble some of the
ideas of the MapReduce framework for different purposes and application
scenarios. Finally, we discuss some of the future research directions for
implementing the next generation of MapReduce-like solutions.Comment: arXiv admin note: text overlap with arXiv:1105.4252 by other author
‘Stand back and watch us’ : Post-capitalist practices in the maker movement
This paper examines the economic practices of maker spaces – open workshops that have increased in number over recent years and that aim to provide access to tools, materials and skills for small-scale manufacturing and repair. Scholarly interest in such spaces has been increasing across the social sciences more broadly, parallel to a growing interest in craft and making in economic geography. However, to rectify the ‘capitalocentrism’ of much existing work, the paper examines the case of a workshop in Edinburgh, Scotland, through the dual theoretical lens of diverse economies and social practice theory. This conceptual approach sees the space as a novel form of economic ‘being-in-common’, providing diverse and contradictory opportunities for post-capitalist practice. The paper draws conclusions regarding the limits and potential of such spaces for sowing the prefigurative seeds for a more inclusive, sustainable and democratic urbanism
Combining Cloud and sensors in a smart city environment
International audienceIn the current worldwide ICT scenario, a constantly growing number of ever more powerful devices (smartphones, sensors, household appliances, RFID devices, etc.) join the Internet, significantly impacting the global traffic volume (data sharing, voice, multimedia, etc.) and foreshadowing a world of (more or less) smart devices, or "things" in the Internet of Things (IoT) perspective. Heterogeneous resources can be aggregated and abstracted according to tailored thing-like semantics, thus enabling Things as a Service paradigm, or better a "Cloud of Things". In the Future Internet initiatives, sensor networks will assume even more of a crucial role, especially for making smarter cities. Smarter sensors will be the peripheral elements of a complex future ICT world. However, due to differences in the "appliances" being sensed, smart sensors are very heterogeneous in terms of communication technologies, sensing features and elaboration capabilities. This article intends to contribute to the design of a pervasive infrastructure where new generation services interact with the surrounding environment, thus creating new opportunities for contextualization and geo-awareness. The architecture proposal is based on Sensor Web Enablement standard specifications and makes use of the Contiki Operating System for accomplishing the IoT. Smart cities are assumed as the reference scenario
International perspectives on engaging the public to anticipate and mitigate the effects of climate change (flooding)
For many years flood stories are documented around the world as history or
legend in almost every region on the planet. Flooding can turn even the most
harmless looking watercourse into a raging torrent of large scale destruction
where any structures may prove no obstacle to its power, it may ruin many
crops which can lead to starvation and take away many people’s lives. Many
governments and international organisations have devised regulations and
management structures to cope with flooding. Although, many nations carry
out actions that are related to elimination or reduction of the probability of
the occurrence or reduction of the effects from unavoidable disasters the lack
of incorporation of the local conditions and vulnerabilities act as a hindrance
to their success. This bespeaks the need to include local knowledge and skills
from specific communities in disaster prevention activities. Hence, in order to
gain an understanding on the international perspectives on flood prevention,
this section of the report outlines the challenges that local authorities face,
the concept of public engagement which has gained its importance in recent
past and its applicability. The report further outlines the ways of achieving
community engagement in flood prevention by bringing forward the solutions
adopted by different countries and finally it identifies three case studies
illustrating good practice on community engagement in flood prevention
A New System Architecture for Heterogeneous Compute Units
The ongoing trend to more heterogeneous systems forces us to rethink the design of systems. In this work, I study a new system design that considers heterogeneous compute units (general-purpose cores with different instruction sets, DSPs, FPGAs, fixed-function accelerators, etc.) from the beginning instead of as an afterthought. The goal is to treat all compute units (CUs) as first-class citizens, enabling (1) isolation and secure communication between all types of CUs, (2) a direct interaction of all CUs, removing the conventional CPU from the critical path, and (3) access to operating system (OS) services such as file systems and network stacks for all CUs.
To study this system design, I am using a hardware/software co-design based on two key ideas: 1) introduce a new hardware component next to each CU used by the OS as the CUs' common interface and 2) let the OS kernel control applications remotely from a different CU. The hardware component is called data transfer unit (DTU) and offers the minimal set of features to reach the stated goals: secure message passing and memory access. The OS is called M³ and runs its kernel on a dedicated CU and runs the OS services and applications on the remaining CUs. The kernel is responsible for establishing DTU-based communication channels between services and applications. After a channel has been set up, services and applications communicate directly without involving
the kernel. This approach allows to support arbitrary CUs as aforementioned first-class citizens, ranging from fixed-function accelerators to complex general-purpose cores
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